In recent years, there has been a growing threat of concealed objects such as weapons and suicide vests housing improvised explosive devices (IEDs) on, for example, a person's body or a vehicle. Current standoff radio frequency (RF) detection systems consist of millimeter wave or terahertz imaging systems looking for image anomalies indicative of concealed objects. However, high-resolution imaging processes are often computationally expensive and time consuming. Further, it may be difficult to find image anomalies due to various factors such as movement of the body or the concealed object, aliases, and other imaging resolution issues. These issues may lead to a low probability of detection and/or a high probability of false alarms. Furthermore, the millimeter wave or the terahertz radar systems require high power transmission due to high RF propagation loss (e.g., greater than 90 dB) at tactical ranges (e.g., 20 m-100 m). However, high power RF transmission can cause a serious radiation hazard problem to persons in proximity to the target area.
Accordingly, what is desired is a low-cost, low-power solution that does not expose persons in a target area to high levels of RF radiation, and which has a high probability of detection of the concealed object and low probability of false alarms.
Further, it is desired to develop a radar solution for real-time detection of concealed objects on a target's body at a tactical stand-off range of, for example, 20 m-100 m (which would permit an operator sufficient time/space to safely nullify a detected threat).